Sure, that 7.4-point edge is slimmer than his 10-point margin of victory in the 2008 election. But the real reason the campaigns are going up in Minnesota is because the Minneapolis and St. Paul media markets reach viewers in Wisconsin and Iowa — two crucial swing states that are in play this year.

(Running ads in states that neighbor battlegrounds is not unusual. The Romney campaign also began buying ads in the Boston market this week. Massachusetts certainly is not in play — New Hampshire, the swing state, is the target.)

Wisconsin pollster Charles Franklin told Business Insider that the specific targets for the Romney campaign are likely Douglas, St. Croix and Pierce counties in Wisconsin. The Minneapolis ads signal that the Republican nominee thinks he has a legitimate shot at winning Wisconsin by cutting into Obama's margins in two counties that the incumbent won in 2008 (Douglas, Pierce) and upping Romney's votes in St. Croix, which John McCain won by a razor-thin margin.